JPH03106435A - Gas distribution device - Google Patents

Abstract

PURPOSE: To enable the reduction of the maintenance cost of a gas inlet and the improved contact of gas with solid particles by coupling a gas distributor to the wall of a vessel, housing many beds therein and disposing a gas inlet means upstream of this gas distributor. CONSTITUTION: A perpendicular vessel 1 is provided with an inlet means 2 for introducing a coke-bearing catalyst, an outlet means 3 for taking-out the regenerated catalyst, an inlet means 4 for introducing an oxygen-contg. gas, an outlet means 5 for taking-out combustion gas and the oxygen-contg. gas distributor 6. This distributor 6 is coupled to the wall of the vessel 1 and has the beds 7 of balls of the same size placed between trays 8. During the normal operation of the apparatus, the hot coke-bearing catalyst particles generated from a riser reactor are introduced through the means 2 into the vessel 1 and the oxygen-contg. gas is introduced through the means 4 into the vessel and are evenly distributed as shown by arrows 9 by the distributor 6. Consequently, the maintenance cost of the gas inlet is considerably reduced and the improved contact of the gas with the solid particles is achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas distribution device, a coke-loaded catalyst regeneration device, and a coke-loaded catalyst regeneration method. The invention relates to a vessel comprising a gas distributor and one or more inlet means for introducing gas upstream thereof, the gas distributor being coupled to a wall of the vessel and one or more beds of elements (
the bed being gas permeable). Such devices can be conveniently used to establish homogeneous gas flow. The device according to the invention can therefore be used in any process requiring a homogeneous gas flow. Suitable processes include coal gasification, combustion processes and catalyst regeneration. This device can also be conveniently used for air slides. This device can be advantageously applied to processes where solid particles come into contact with a gas stream. The device is very suitable for use in fluidization processes in which solid particles, such as catalyst particles, are brought into contact with an upward gas flow. In such a process the device is suitably applied in such a way that the fluidized particles are kept in flow with respect to the gas distributor.
In that way contact between the solid particles and the gas inlet means is avoided. Therefore, erosion problems that occur due to such contact when using conventional gas inlet means such as nozzled distribution pipes are advantageously avoided. As a result, gas inlet maintenance costs can be significantly reduced. Furthermore, an improved gas distribution is established, ie over the entire area of the vessel, so that improved contact of gas and solid particles can be obtained. The gas distributor preferably has a circumference extending substantially along the wall of the vessel. The elements are preferably placed between trays that are impermeable to the elements. In this way the element is retained in the bed even when a significant gas flow is applied, especially if the bed also comprises an upper tray. The trays in the apparatus of the invention may be of the usual type, for example sieve trays made of perforated plates and having a circumference attached to the walls of the vessel. Suitably the tray consists of a screen constructed of rondo groups, for example. In principle, the elements in the floor can be of any shape. The element is suitably shaped to provide a homogeneous flow resistance across the bed. The elements are suitably of substantially the same dimensions. Preferably, the element is between 0.5 and 1 (lu+, more preferably between 1 and
It is a sphere with a diameter in the range 4-. The diameter of the sphere is usually
It is 2 to 50 times the diameter of the solid particles mixed with the upward gas. Suitably, the element is made of an inert material, such as a ceramic material, an inert steel or a carrier material for catalyst particles. Preferably the element is made of ceramic material. The element is suitably sized or arranged such that no solid particles brought into contact with the gas pass through the bed of the element. In this way contact between the solid particles and the gas inlet means is avoided. The elements can be (im)movable with respect to each other. It will be appreciated that if the elements were movable relative to each other, the floor would not be filled with spheres over its entire height. The floor is preferably filled with elements over at least 99% of its height. The device according to the invention can be suitably applied as a regeneration chamber in a catalytic cracker. The invention therefore also provides one or more inlet means for introducing the coke-loaded catalyst, one or more inlet means for introducing the oxygen-containing gas into the lower part of the vessel,
one or more outlet means for removing regenerated catalyst particles and one for removing combustion gases at the top of the vessel
or more outlet means for regenerating coke-laden catalyst particles, wherein the oxygen-containing gas distributor comprises an inlet means for introducing coke-laden catalyst and an oxygen-containing Regarding said device being arranged substantially horizontally in the vessel between the inlet means for the introduction of gas. A preferred embodiment of the apparatus according to the present invention, the regeneration chamber, will be explained below with reference to FIG. The apparatus shown in Fig. 1 has an inlet means (
2), a substantially vertical pipe comprising outlet means for removing regenerated catalyst (3), inlet means for introducing oxygen-containing gas (4), outlet means for removing combustion gas (5) and an oxygen-containing gas distributor (6); Contains tank (1). The distributor (6) comprises a bed (7) of substantially identically sized spheres (shown only partially and enlarged) placed between the trays (8). During normal operation of the apparatus depicted in FIG. 1, hot coke-laden catalyst particles originating from the riser reactor are introduced into the vessel (1) through the inlet means (2). The oxygen-containing gas is introduced into the vessel via the inlet means (4) and the upward gas flow is then homogeneously distributed by the distributor (6) as shown by the arrows (9). The incoming catalyst particles are thus fluidized by a homogeneous gas upward flow and an optimal mixing of catalyst particles and oxygen-containing gas is established. During fluidization, coke is removed from the catalyst by 50%.
It is burnt off at a temperature of 0 to 800°C and a pressure of 1 to 5/<1) and the resulting combustion gases are removed by outlet means (5). The resulting regenerated catalyst is removed from the tank via outlet means (3). The outlet means (3) can also be arranged to extend beyond the distributor (6) without causing a substantial change in operation. The distance between the rondos is usually smaller than the average diameter of the ball, so the ball is kept within the floor. The present invention also provides a method for regenerating catalyst particles using a regeneration chamber as described above, wherein an oxygen-containing gas is introduced into the bottom of the vessel by one or more inlet means, the catalyst being introduced by one or more inlet means. introducing in such a way that it is fluidized, burning out the coke deposited on the catalyst and thereby achieving a pressure drop across the oxygen-containing gas distributor, and withdrawing the regenerated catalyst particles from the top of the vessel. The reproduction method includes: The temperature applied in the regeneration process can range from 500 to 800°C and the pressure applied can range from 1 to 5 bar.

[Brief explanation of drawings]

Figure 1 is a schematic longitudinal sectional view of the regeneration chamber. l...tank,
2... Inlet for introducing coke-loaded catalyst, 3... Outlet for taking out regenerated catalyst, 4... Inlet for introducing oxygen-containing gas,
5... Combustion gas outlet, 6... Oxygen-containing gas distributor.

Claims (1)

Claims: (1) A vessel comprising a gas distributor and one or more inlet means for introducing gas upstream thereof, the gas distributor being coupled to a wall of the vessel and one of the elements. or more beds, the beds being gas permeable. 2. The apparatus of claim 1, wherein the gas distributor has a circumference extending substantially along the wall of the vessel. (3) The device of claim 1 or 2, wherein the element is placed between trays that are not permeable to the element. (4) A device according to any one of claims 1 to 3, wherein the elements are of substantially the same size. (5) A device according to any one of claims 1 to 4, wherein the element is made of an inert material. (6) The device of claim 5, wherein said element is made of a ceramic material. (7) The device according to any one of claims 1 to 6, wherein the element is a sphere. (8) A device according to claim 7, wherein the sphere has a diameter in the range from 0.5 to 10 mm. (9) one or more inlet means for introducing contaminated catalyst particles, one or more inlet means for introducing oxygen-containing gas into the lower part of the vessel, and one or more inlet means for removing regenerated catalyst particles; a substantially vertical tank including one or more outlet means and one or more outlet means for removing combustion gases at the top of the tank, the gas distributor including an inlet means for introducing coke-loaded catalyst; 9. Apparatus according to any one of claims 1 to 8, for regenerating coke-laden catalyst particles, which is arranged substantially horizontally in the vessel between the inlet means for the introduction of oxygen-containing gas. (10) introducing an oxygen-containing gas into the bottom of the apparatus according to claim 9 by one or more inlet means;
The catalyst introduced by the one or more inlet means is introduced in such a way that it is fluidized, burns off coke deposited on the catalyst, and thereby achieves a pressure drop across the oxygen-containing gas distributor. and removing the regenerated catalyst and combustion gases from the top of the apparatus by means of an outlet means.